Prior art technology of general interest in connection with the present invention are the procedures for producing compounds such as .alpha.-(1-R-3-pyrrolidinyl)-.alpha.,.alpha.-diphenylacetamides (and -acetonitriles) and .alpha.-(1-R-3-pyrrolidinyl)-.alpha.-phenyl-.alpha.-(2-pyridyl)acetamides (and -acetonitriles) which are disclosed in U.S. Pat. Nos. 3,192,206; 3,192,210; 3,192,221; 3,102,230; and 4,002,766.
Also of interest are the synthesis methods for producing antidepressant 3-disubstituted methylenepyrrolidines which are described in U.S. Pat. No. 3,732,247. The methylenepyrrolidines of the patent correspond to the formula: ##STR2## wherein R is selected from the group consisting of hydrogen, lower-alkyl, phenyl-lower-alkyl, substituted phenyl-lower-alkyl, cycloalkyl, phenoxy-lower-alkyl, phenylamino-lower-alkyl, and substituted phenyl, said lower-alkyl being limited to contain 2 to 8 carbon atoms when R.sup.1 and R.sup.2 are both phenyl; R.sup.1 is selected from the group consisting of lower-alkyl, phenyl-lower-alkyl, cycloalkyl, phenyl and substituted phenyl; and R.sup.2 is selected from the group consisting of phenyl and substituted phenyl.
U.S. Pat. No. 4,133,881 describes the production of a class of .alpha.-(1-R-3-azetidinyl)-.alpha.-phenyl-.alpha.-substituted-acetamides and -acetonitriles corresponding to the following formula: ##STR3## wherein R represents hydrogen, lower alkyl, lower cycloalkyl or phenyl-lower-alkyl, R.sup.1 represents phenyl or 2-pyridyl, and Y is carbamoyl or cyano, which compounds exhibit antiarrhythmic activity.
Accordingly, it is a main object of the present invention to provide an improved process for producing methylene-cycloamine compounds such as 3-methyleneazetidine compounds which are characterized by one or more pharmacological properties useful for counteracting specific physiological abnormalities in humans and other mammals.
It is another object of this invention to provide a new and efficient method for converting a compound such as .alpha.,.alpha.-diphenyl-.alpha.-(1-ethyl-3-pyrrolidinyl)acetamide to a methylenecycloamine compound such as 1-ethyl-3-diphenylmethylenepyrrolidine.
Other objects and advantages shall become apparent from the accompanying description and examples.